What is Tarsal Tunnel Syndrome?
Tarsal tunnel syndrome (TTS) is rare. It is an injury to the tibial nerve, also known as tibial neuralgia. TTS is commonly termed “carpal tunnel syndrome of the ankle.” To understand why this happens, some basic understanding of the foot anatomy is important.
We have 26 bones, 33 joints, 19 muscles, 107 ligaments as well as nerves within each foot. Our forefoot is the from the tips of our toes to the arch of our foot which has 19 bones and joints. It takes these combined structures to collective and systematically works together to allow for movement and sensation within our feet.
Most of our foot movements are generated from muscles within or lower legs. These muscles generate the power we need to walk, run, skip, hop, jump, or swim. They pull on tendons within the foot to allow for joint and bone movement. Ligaments are meant to stabilize joints, to keep them together throughout the movement.
The bones within our toes are called phalanges and bones in the middle of our foot are called metatarsal bones. Midfoot is considered the area of our arch and the ankle. We have five bones (Cuboid, Navicular, and 3 Cuneiform bones) which are compact and tightly held together by a band of ligaments. The hindfoot is the heel which has two bones (Calcaneus and Talus).
The two bones in each leg, the Tibia, and Fibula, meet up with the talus bone in the foot. The bony prominence on the inside of your ankle is called the medial malleolus which is the lower end of the tibia bone. The tibia fits neatly into the talus bone which is where the talus tunnel exists.
The tibial nerve is a branch of the sciatic nerve in the lower back. As the sciatic nerve transcends down the leg towards the ankle, it becomes the tibial nerve as it passes through the knee. The nerve runs down the leg, posteriorly to the tibia. As it arrives at the ankle, it passes through from behind the medial malleolus towards the front of the foot. From here, the tibial nerve branches off again into three separate branches to provide function and sensation throughout the bottom of the foot.
When we experience ankle trauma or possibly an underlying medical condition like arthritis, the tibial nerve may become irritated and entrapped within the tarsal tunnel, which can lead to pain and numbness in the ankle and the bottom of the foot.
What causes a tarsal tunnel syndrome?
Tarsal tunnel syndrome is rare. The most common causes are usually either a previous trauma which has now caused damage to the tunnel, or an underlying medical condition such as osteoarthritis or rheumatoid arthritis.
There are other factors that may put someone at a higher risk of experiencing TTS, and they are:
- Ankle sprain
- Bone spur
- Flat feet
- Ganglion cyst
- Lesion (e.g. tumor)
- Varicose vein
Symptoms of Tarsal Tunnel Syndrome
Symptoms vary from person-to-person; however, the most commonly reported symptoms of TTS are:
- Burning, numbness, or tingling at the heel or bottom of the foot
- Burning, numbness, or tingling in the big toe
- Disruptive sleep at night due to pain
- Increased pain with prolonged weight bearing activities
- Sharp pain, especially with dorsiflexion (pointing foot upwards)
- Swelling at the ankle
How is tarsal tunnel syndrome diagnosed?
Not all foot pain is the same; there may be an underlying medical condition such as diabetes, arthritis, stress fractures, or even complex regional pain syndrome (CRPS) affecting your foot. It is advised you visit with your local health care provider to diagnose the symptoms you may be experiencing properly.
Your physical therapist (PT) or physician can determine if you have TTS by completing a review of your medical history as well as a thorough physical exam of the ankle and foot. The goal is ruled out more common foot pain conditions such as plantar fasciitis, stress fracture, or Achilles tendonitis. Two assessments your health care provider will perform Tinel’s sign and what is known as tensing.
The Tinel’s sign is where your PT or doctor will tap behind the medial malleolus, just over the tibial nerve. Tensing is when your PT or doctor dorsiflex your foot to put the tibial nerve on the stretch. With both Tinel’s sign and tensing, a positive result is when symptoms are reproduced.
In more severe cases, or if there is suspicion of another condition, your doctor may order an X-Ray, MRI (magnetic resonance imaging), or EMG (electromyography). An X-Ray will allow the doctor to look at your bone structure. An MRI will take an imagine of not only your bones but also your soft tissue within the area as well. An EMG is a nerve conductivity test. It measures how well your nerve is, or is not, communicating.
Treatment of Tarsal Tunnel Syndrome
Unless significant trauma has occurred to the ankle, it is recommended to start with conservative treatment like PT. Your PT will complete a full evaluation and will team with you on establishing functional goals.
To start, your PT will work with you on managing symptoms. He or she may customize a foot orthotic to properly support the foot structure and “unload” the area of the tarsal tunnel. Also, your PT may also perform nerve glide exercises to improve movement of the entrapped nerve.
Strengthening and balance activities will be introduced by your PT when appropriate. Strength and balance activities are critical to the healing process. As the nerve heals, gaining strength and functional movements within the ankle and foot will prevent the injury from reoccurring.
In rare cases, if the nerve is highly irritated and inflamed, your doctor may prescribe medications or inject the nerve at the tarsal tunnel. The goal is to reduce irritation so you can tolerate PT interventions. If there is a significant injury to the nerve or the nerve does not respond to conservative care after 6-months, tarsal tunnel release surgery may be indicated.
Your physician will ensure you understand how the procedure is performed as well as the risks. With a TTS release surgery, the surgeon will cut the laciniate ligament, which is the main ankle stabilizer ligament, to open up space for the tibial nerve to pass through more freely. Typical recovery time from this surgery is at least two months.
PT is recommended after surgery. Your surgeon will prescribe when he or she would like for you to start PT. During rehabilitation, managing swelling and pain are the first goals. When appropriate, your PT will start range of motion and strengthening exercises. The goal is to stabilize and strengthen the ankle to return to functional activities safely.
Early intervention is always the best when managing foot pain. The sooner you address your symptoms, the more likely conservative care will work for you. As a consumer of health care, you have a choice in finding the right provider for you. Do your homework and search for a health care provider, like a physical therapist, with excellent outcomes, great customer reviews, and can provide you the care you need for a reasonable cost.
Most states have direct access to a physical therapist, meaning you can go directly to a physical therapist without a physician order. To determine if your state has direct access, please visit the American Physical Therapy Association’s website Physical Therapy Direct Access By State.
To get started with conservative care today, you can find a highly qualified PT in your area. There are many qualified PTs, so to find one near you, please click on Find A Clinic. This link will help you find a PT that has top national rankings for treating the foot and ankle.